The STRAW+10 system is the tool doctors and researchers use to put clear labels on the menopause transition. In short: it divides reproductive ageing into numbered stages, from -5 to +1c, based on changes in your menstrual cycle — once you know your stage, you have a good idea of which symptoms to expect and where to put your attention. The transition lasts years, but its landmarks can be recognised with real precision.

What the STRAW+10 system is:

STRAW stands for Stages of Reproductive Aging Workshop, and the +10 reflects that the system was extended to cover the early years after menopause. Published in its current form by Harlow and colleagues in 2012, it is regarded as the gold standard for staging reproductive ageing. In practice it gives clinicians a shared language: instead of vague talk about 'the change', they can state exactly which stage a woman is in and compare studies and treatments with one another.

What the STRAW system is not:

It helps to be clear about what the system claims and what it does not, because it is often asked to carry more weight than it can.

It is not a diagnosis. It does not tell you what is causing a symptom, and it does not identify a disease. It places you on a timeline of reproductive ageing, which is a different question.

It is not a blood test. Hormone levels swing widely during the transition. A single measurement can sit in the normal range on a day when your cycle is already changing. It can look unusual on a day when nothing is wrong. That variability is exactly why the staging was built on the cycle instead.

It is not a prediction of your own timeline. The stages describe the order in which things happen and the pattern most women follow. How long you spend in any one of them is an individual matter. The system does not tell you when your own symptoms will start, peak or settle.

And it is not a treatment guide on its own. Knowing your stage tells a clinician what is expected at this point. It does not decide what should be done about it.

Why the menstrual cycle is the compass:

You might wonder why staging does not rely on blood tests. Because hormones swing widely from one month to the next during this phase, which makes them unreliable markers. The menstrual cycle, by contrast, is observable, free, and tracks ovulation and hormones fairly faithfully: as ovulation becomes less frequent, the bleeding pattern shifts in a predictable way. The overview: the system starts in adult reproductive life, moves through two phases of perimenopause, marks the moment of menopause as 0, and continues into postmenopause.

Why the numbering runs backwards, then forwards:

A first look at a stage like -3 or +1b is puzzling, and the logic underneath is simpler than it appears.

The system counts from the final menstrual period, which is the one fixed point in the whole process. Everything before it carries a minus sign, running backwards. The milestone itself is 0. Everything after it carries a plus sign, running forwards.

The final period is used as the anchor because it is the only landmark in the transition that can be confirmed. Once it is behind you, it is unambiguous. Everything else — the first cycle that varied, the first gap, the first hot flash — has to be judged while it is still happening, which is much harder.

The letters matter too. The stages after the milestone are divided further, because the years that follow are not one uniform stretch. The early part of postmenopause is when the body is still settling after the hormonal upheaval of the transition. Later the picture is steadier, and attention shifts toward long-term prevention.

The map of stages, from -5 to +1c:

  • Premenopause (-5): regular, predictable cycles with no significant changes — the normal reproductive period
  • Early perimenopause (-4 to -3): cycles begin to vary by more than 7 days from your usual length; this shift signals the start of the transition
  • Late perimenopause (-2 to -1): gaps of 60 or more days between periods; the most active phase of the transition, strongly linked with hot flashes (VMS) and sleep disruption
  • Final Menstrual Stage (0): the milestone of 12 consecutive months without a period, confirmed retrospectively; the average age in the SWAN Study is 52.5
  • Postmenopause (+1a, +1b, +1c): the years after the milestone, when the focus shifts to long-term cardiovascular, bone and cognitive health

Reading your own cycle against the stages:

Using the system for yourself comes down to noticing two things: how much your cycles vary, and whether you have skipped any altogether.

Variation means a cycle that is noticeably longer or shorter than what has been normal for you. Most women have a fairly stable personal pattern, so a change is usually obvious from your own history rather than from any outside standard. Skipping means a gap between periods long enough to make you wonder whether they have stopped for good — and then a period arrives and answers the question.

That stop-start quality is the signature of the transition. A single long gap settles nothing, because the next cycle may be perfectly ordinary. A run of regular cycles does not prove the transition has not begun either.

This is why the system asks for a pattern rather than a moment. One unusual cycle is information. Several, over months, is a direction. It is also why a calendar does more work here than any single test.

What the SWAN data tells us:

The SWAN Study, which follows thousands of women through the transition, has confirmed that the bleeding patterns defined by STRAW+10 track symptom severity well. In practice, sleep disturbance and vasomotor symptoms rise significantly in stage -2 — late perimenopause — and peak around the final menstrual period. For you, this means a stretch of intense symptoms near the end of the transition is an expected pattern, not a sign that something is wrong — and that, typically, things begin to settle after the 12-month milestone.

What else can change the bleeding pattern:

A changing cycle is the expected story of the transition, which makes it easy to attribute every change to it. That can hide something else, because the transition is not the only thing that alters bleeding.

  • Fibroids and polyps: growths in the uterus that can make periods heavier, longer or more frequent
  • Thyroid problems: an overactive or underactive thyroid can disturb the cycle in either direction
  • Bleeding disorders: conditions that affect clotting can make periods unusually heavy from the start
  • Stress, illness and weight change: all can interrupt ovulation and shift the pattern
  • Medicines: some prescriptions, including hormonal contraception, change bleeding directly
  • Pregnancy: still possible during perimenopause while cycles are still occurring

What distinguishes the transition is the shape of the change. Cycles become variable, then spaced out, in a pattern, without another explanation. A pattern that does not fit that shape is a reason to ask a clinician to look. That includes bleeding much heavier than your normal, bleeding between periods, or bleeding that returns after the milestone has passed.

Where you are right now:

If your cycles have started to vary by more than 7 days, you are, by the STRAW system, at the beginning of the transition. If you have had gaps of 60 days or more between periods, you are in late perimenopause, the phase with the most intense symptoms. If a full year has passed without a period, you have reached stage 0 and are officially in postmenopause. Track your period dates for a few months and take the record to your clinician: together you can identify your stage and decide what to watch next.

Keeping a record that is actually useful:

Tracking is what makes staging possible, and a simple record is enough. A note in a phone calendar or a paper diary works as well as an app.

  • The first day of each period, so the length of each cycle can be worked out
  • How heavy the bleeding was, in your own words — lighter, usual, heavier, or flooding
  • Any bleeding between periods, however light
  • Symptoms alongside the dates: hot flashes, sleep, mood, headaches
  • Anything that might explain a change, such as illness, travel, stress or a new medicine

Two habits make the record more useful. The first is writing it down as it happens rather than reconstructing it later, because memory for dates is poor. The second is bringing the record with you rather than a summary from memory. A clinician can read a pattern from a few months of dates. A woman describing 'irregular periods' gives them far less to work with.

Why the labels matter:

Stages are not an academic exercise. They help you know what to expect: in late perimenopause, for example, hot flashes and broken sleep are common, while in postmenopause attention shifts to long-term prevention — bones, heart, brain. A shared language also helps doctors give you consistent care, whichever clinician you see.

A stage is not a symptom score:

One of the commonest misunderstandings is that the stage predicts how bad you will feel. It does not. The stages describe the bleeding pattern, which reflects what the ovaries are doing. Symptoms are a separate story.

Two women in the same stage can have very different experiences. One may have hot flashes that break her sleep most nights. Another may have almost none. The staging system places them side by side, because it is not measuring symptoms. It is measuring where they are in the process.

Symptoms do follow a broad pattern across the stages, which is why the system is useful for anticipating what may come. But a mild experience is not a sign that you are in an earlier stage, and a difficult one is not a sign that something has gone wrong. It is a sign that symptom burden varies between women, for reasons that are not fully understood and are not captured by the map.

That has a practical consequence. If your symptoms are troubling you, that is a reason to seek help in its own right, whatever stage you are in.

When the map does not fit:

The system was built around spontaneous, natural menstrual cycles, and there are situations where it has less to work with.

If you use hormonal contraception, the bleeding you experience may be a withdrawal bleed rather than a cycle. The staging system cannot read a pattern that the medication is producing. That is a limitation of the tool, not a problem with you.

If your periods stopped suddenly — after surgery, or after treatment that affects the ovaries — the transition did not follow the gradual path the stages describe. The stages still apply in a general sense, but the anchor point arrives without the run-up.

And if the transition begins much earlier than expected, the staging language can feel beside the point. The framework was designed around the typical path. Being outside the typical path is a reason for closer attention, not a reason to be dismissed.

In each case the useful step is the same. Say plainly how your periods started, changed or stopped, and let the clinician work out what the pattern means.

In short:

The STRAW+10 system arranges the transition into clear stages based on the menstrual cycle: variations of more than 7 days mark the start, gaps of 60 days or more mark late perimenopause, and 12 months without a period means menopause. SWAN data show the most intense symptoms come near the end of the transition and ease afterwards. Whatever your stage, knowing where you are helps you understand what comes next.